Field
The present disclosure generally relates to robots, and more particularly, to systems and methods for controlling locomotion of a robot with treads coupled to independently controlled axes.
Background
Various wheel arrangements have been developed to improve the maneuverability of vehicles. A conventional vehicle with independent wheels, such as a car, uses Ackerman steering to turn. Ackerman steering is desirable when paired with a front or rear wheel differential. Still, Ackerman steering is not desirable for use with vehicles that turn in place.
In some cases, treads, such as tank treads, may be used to provide locomotion to a vehicle. The treads may be desirable for all terrain traction, but are inefficient for turning in place. That is, to follow a curved path, the conventional treaded vehicle uses a skid steer to rotate. Still, when used indoors or on fragile surfaces, the treads may damage the surface.
In other cases, vehicle drive systems, such as a drive system used for a robot, may use a multi-axis rotation that allows each wheel to drive in a forward/reverse direction and also to rotate in place. Such wheels may also be referred to as wild swerve wheels. The multi-axis wheels are similar to actuator driven caster wheels, such as the wheels of a shopping cart or office chair. Still, conventional multi-axis wheels are not independently operated.
In industrial vehicles, such as forklifts and tractors, the maneuverability of vehicles can be improved by the provision of omni-directional wheels. One such wheel design is the Mecanum wheel, which has been used in forklifts, wheelchairs, and other applications. Still, because of the shape of the rollers for the Mecanum wheel, only a small area on the outer circumference of each roller contacts a given surface when in operation, which results in a reduced ability to navigate on various surfaces. Additionally, because of the shape of the Mecanum wheel, vehicles using this type of wheel have a raised profile. Thus, vehicles using a Mecanum wheel may not have a low profile for improved maneuverability.
In some cases, an omni-direction tread system is specified to include treads that rotate in various directions, such as forward, backwards, left, and right. Still, the conventional omni-direction tread system includes external belts and pulleys to rotate the treads. Moreover, the electronics of the conventional omni-direction tread system are external to the treads. Thus, because the components of the conventional omni-direction tread system are external, the components may be prone to damage. Moreover, the components are not modular and may be difficult to replace.
Thus, it is desirable to provide an omni-direction tread system that is compact with replaceable parts. The tread system may include independent multi-axis wheels, such as sprockets within a tread, so that the treads may rotate in various directions, such as forward, backwards, left, and right. Furthermore, the components for providing locomotion to the treads should be defined within the tread so that the components of the vehicle are less prone to damage.